1. The problem statement, all variables and given/known data A 3kg box is held up high in the air by a a rope with negligible mass. The rope's tension is depends on the function of time T(t) = (36N/s)*t. The box is at rest at t = 0. Only the forces tension and gravity act on this box. a) What is the velocity at t = 1.0s? b) What is the velocity at t = 3.0s? 2. Relevant equations I think that my acceleration formula is the problem, but I don't know why. a(t) = (2.2m/s^3)t - 9.8m/s^2 I took out the mass to get the box's acceleration and then I just broke up the applied acceleration from the constant gravitational acceleration. v(t) = (1.1m/s^3)t^2 - (9.8m/s^2)t This is my integral of the acceleration. 3. The attempt at a solution a) a(1s) = 1.1m/s - 9.8m/s = -8.7m/s but the book's answer is -3.8m/s. I just can't grasp how I am wrong.